In such mills material ground on the grinding table moves outward under centrifugal force, owing to the rotation of the grinding table, over the nozzle ring separation area, where the material undergoes nozzle ring separation. Material is both pneumatically conveyed upwards and inwards to the area above the grinding table by the gas stream from the nozzle ring separation area or falls through the nozzle ring separation areas to either a process by which the material is re-introduced to the mill or is removed from the process. This gas stream is employed for cooling, heating or drying the material inside the mill and transporting said material to the separator. The gas distribution and velocity through the nozzle ring separation area can be optimally adjusted to suit the specifics of the material. Finer particle fractions of ground material are suspended in the conveying gas and carried upwards inside the mill housing into the separator, while coarser particle fractions, too heavy to remain suspended in the conveying gas, fall down indiscriminately to various areas of the mill table, grinding track, outer mill housing and nozzle ring separation area whereupon material repeats the process of nozzle ring separation. Material can be subject to such repeated lift and fall cycles before reaching the separator and in this way a substantial amount of material can be conveyed randomly above the grinding table without landing on its grinding path for renewed grinding, which reduces the mill efficiency and particularly causes increased and unnecessary energy consumption. It is the object of the invention to overcome these mill inefficiencies.